(1) Field of the Invention
The present invention relates to a three-dimensional measuring apparatus for measuring a shape of an object by projecting multi-slit lights on the object to obtain a three-dimensional measurement.
(2) Description of the Related Art
In the fields involving a three-dimensional visual function for recognizing an object to be measured for use in a robot or other various automatic apparatuses, or a shape input apparatus for measuring the shape of the object to be input, there is a known arrangement in which a slit light is irradiated by a projector onto the object to be measured. The object is then scanned and imaged by an imaging unit from an angle different from the irradiating direction to calculate the distance from the observation point to the slit light irradiated point based on the triangulation. Thus, the shape of the object to be measured is recognized.
Instead of scanning the slit light, a multi-slit projector which irradiates a plurality of parallel slit lights to enable a plurality of points to be measured at the same time can be used. In this case, the resolution in the measurement of the object to be measured is determined by the resolution of the imaging apparatus and the pitch between the slit lights irradiated from the projector. Thus, the resolution in the measurement of the object is not accurate and must be improved.
In the three-dimensional multi-slit measuring apparatus, multi-slit lights are projected onto an object to be measured, the projected image is picked up by an image pick up unit such as a television camera, and a reference slit light is determined among the projected multi-slit lights to calculate a distance from an observation point to a coded pattern irradiated point of the object to be measured. In this apparatus, however, the speed at which the measurement is made must be increased.